Transcript Kepler`s Law - New Mexico Tech

Astronomy/Solar System
Presentation for
Science Olympiad
Presented by the New Mexico Tech
Astronomy Club
November 5th, 2010
History and Formation of Solar
System
-How old is the solar system? The solar
system is 4.57 billion years old.
-How did the solar system form?
Protostellar cloud collapsed into a massive
disk, first formed the sun, and over the
years formed our solar system.
-How much of the solar system’s mass is
solely the mass of the Sun? 99.86% of the
solar system’s mass is in the sun.
Images courtesy of SOHO consortium, an ESA and NASA joint
project.
Sun
• What is the Sun’s temperature at the core? 15
million degrees Kelvin.
• Compared to nearby stars, the Sun is luminous,
hot, and big.
• Compared to apparently bright stars, the Sun is
dim, cool, and small.
• Compared to stars in globular clusters, the Sun is
very young.
• Compared to stars in open (galactic) clusters, the
Sun is very old.
Magnetic Field
• The sun is a magnetically active star.
• Its magnetic field is strong, and changes
continually year-to-year and reverses its
polarity about every eleven years, this cycle is
called they Schwabe Cycle.
• The sun’s magnetic field causes solar activity,
including sunspots on its surface, solar flares,
and solar winds.
Layers of the Sun
-Corona
Solar Wind
-Chromosphere
Prominences
Solar Flares
-Photosphere
Sunspots
Subsurface Flows
-Internal Structure:
Convection zone
Radiative zone
Inner Core
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Copyright:Wikipedia - GNU Free Documentation License
The Sun’s Lifecycle
• The Sun was formed about 4.57 billion years
ago when a hydrogen molecular cloud
collapsed.
• It is about halfway through its main-sequence
evolution, during this time, nuclear fusion
reactions in its core fuse hydrogen into helium.
• It will spend approx. 10 billion years as a main
sequence star
Auroras
• What causes Auroras? When
charged particles from the
solar winds hit the magnetic
field of Earth and are brought
close to the Earth’s
atmosphere.
• Where do auroras most often
occur? They occur in high
northern and far southern
latitudes but have occasionally
been seen in the equator.
• Why are they seen in the
northern and southern
latitudes? That is where the
charged particles reach closest
to Earth.
Terrestrial and Gaseous Planets
Terrestrial Planets
• What is another name for Inner Planets? Terrestrial
planets.
• Name the Inner Planets. Mercury, Venus, Earth, Mars.
• What are their similarities?
-They are all composed mostly of rock, and heavy metals.
-Closest to the sun, their cores are mostly made of iron,
and also have varied terrain such as volcanoes,
canyons, mountains, and craters.
-The terrestrial planets have few or no satellites.
• How do Terrestrial Planets differ from Gaseous?
Terrestrial planets are much smaller, and do not have
planetary rings like Gaseous planets.
Mercury
• Distance:57.91 million km
from the Sun
• Diameter: 4,878 km
• Mass: 3.3x10^23 kg
• Density: 5.43 g/cm
• Satellites: None
• Surface Temperature: 166.7
degrees Celsius
• Rotation: 58.65 Earth days
• Axial Tilt: none
• Orbital period: 87.97 Earth
days
• Atmosphere consists of:
Helium, Sodium, Oxygen
Venus
• Distance: 108.2 million km from
the sun
• Diameter: 12,102 km
• Mass: 4.87x10^24 kg
• Density:5.25 g/cm^3
• Surface Temperature: more than
500 degrees Celsius
• Satellites: None
• Orbital Period: 224.7 Earth days
• Rotation: 243.01 Earth days
• Axial Tilt: 177.3
• Atmosphere consists of:
Poisonous carbon dioxide and
sulfuric acid
Earth
• Distance:149,597,870 km from
the Sun
• Diameter: 12,756 km
• Mass: 5.24x10^24 kg
• Density: 5.52 g/cm^3
• Surface Temperature: 15
degrees Celsius
• Satellites: Luna
• Orbital Period: 365 days
• Rotation: 24 hours
• Axial Tilt:23.5
• Atmosphere consists of:
• Nitrogen and Oxygen
Mars
• Distance: 227.94 million km
from the Sun
• Diameter: 6.786 km
• Mass: 6.42x10^23 kg
• Density: 3.95g/cm^3
• Surface Temperature: ranges
from -5 to -87 degrees Celsius
• Satellites: Phobos, Deimos
• Axial Tilt: 25.19
• Rotation: 24.62 Earth days
• Orbital period: 686 Earth days
• Atmosphere consists of:
Carbon Dioxide, and nitrogen
Jovian Planets
-Gas planets in the Solar System
-Last 4 Planets in the Solar System
-Mostly made up of Hydrogen, Helium,
Ammonia and Methane
-Jovian Planets:
Jupiter, Saturn, Uranus, Neptune
Jupiter
-Distance From Sun: 788.3 Million km or
5.2 AU
-Diameter: 142,984 km
-Mass: 1900x10^24 kg
-Density: 1.33 g/cm3
-Major Satellites: Io, Europa, Ganymede,
Callisto
-Surface Temperature: 14.8-19.8 degrees
Celsius
-Atmosphere: Hydrogen and Helium with
traces of Methane and Ammonia
-Seasons: No real changes in Seasons
due to its 3˚ Tilt.
Features: Great Red Spot
Saturn
-Distance from Sun: 1,426.98 Million km
or 9.54 AU
-Diameter: 120,536 km
-Mass: 569x10^24 kg
-Density: .69 g/cm3
-Major Satellites: Titan, Rhea, Dione
-Atmosphere: Hydrogen-Helium. Weak
reactions in atmosphere attribute to its
color
-Rings: Made up of billions of particles of
rock and ice.
-Seasons: No real changes due to its
distance from the sun. Has a 26˚ axis tilt
Uranus
-Distance From Sun: 2,870.99 Million
km or 19.19 AU
-Diameter: 51,118 km
-Mass: 86.6x10^24 kg
-Density: 1.29 g/cm3
-Major Satellites: Oberon, Miranda
-Surface Temperature: -197.15
degrees Celsius
-Atmosphere: Hydrogen, Helium,
Ammonia. Absorption of Methane
gives it its blue color
-Rings: Faint Rings
-Seasons: 20 Year long Seasons due
to its 82˚ axis tilt
Neptune
-Distance from Sun: 4.497 Million km or
30 AU
-Diameter: 49,528 km
-Mass: 103x10^24 kg
-Density: 1.64 g/cm3
-Major Satellites: Triton
-Surface Temperature: -200.15 degrees
Celsius
-Atmosphere: Hydrogen, Helium,
Methane, Ammonia
-Rings: Faint Rings
-Seasons: No big changes due to its
distance. Brightness in clouds in
southern Hemisphere. Has 28˚ axis tilt.
Lunar Eclipses.
• Lunar eclipses—occurs only when the moon
passes behind the earth so that the earth
blocks the sun’s rays from striking the moon.
Solar Eclipses
• Solar eclipses—occurs when the Moon passes
between the Sun and Earth, and the Moon
fully or partially covers the Sun as viewed
from a location on Earth. This can only happen
during a new moon.
Lunar Phases
• What are the lunar
phases? The phase of the
moon is the appearance
of the illuminated portion
of the Moon as seen by
the observer. This cycle
takes 29.5 days. Don’t get
this confused with the
27.3 days it takes the
Moon to orbit the Earth.
Planetary phases
• What is Planetary
phases? Planetary
phases describe the
appearance of the
illuminated section of a
planet.
• To the left is Venus’s
planetary phases.
Dwarf Planets
-Objects
in orbit around the Sun that can sustain its shape
due to self-gravity.
-The difference between a planet and a dwarf planet is
that a dwarf planet has not cleared other objects from its
orbit.
-Dwarf Planets: Ceres, Pluto, Haumea, Makemake, Eris
Ceres
-Distance from Sun: 413,832,587
km or 2.76 AU
-Diameter: 950 km
-Density: 2.07 g/cm3
-Satellites: None
Pluto
-Distance from Sun: 5,913.52
Million km or 39.5 AU
-Diameter: 2,300 km
-Density: 2.03 g/cm3
-Satellite: Charon
Haumea
-Distance From Sun: 6452 Gm or
43.1 AU
-Diameter: 1436 km
-Density: ~ 3 g/cm3
-Satellites: Hi’iaka, Namaka
Makemake
-Distance From Sun: 6850.3 Gm or
45.8 AU
-Diameter: 1500 km
-Density: 2 g/cm3
-Satellites: None
Eris
-Distance From Sun: 10.12 Gm or
67.67 AU
-Diameter: 2500 km
-Density: 2.25 g/cm3
-Satellites: Dysnomia
Solar System Objects
-Asteroid: Rocky and metallic
bodies within the solar system that
orbit the sun.
-Meteoroid: A small rock or boulder
classified as debris from the solar system.
Any debris that enters the atmosphere is
known as a meteor and any debris surviving
an impact on the ground is known as a
meteorite.
•What is the difference between a
Meteoroid, Meteor and a Meteorite?
-Comets: A chunk of dust and ice
left over from the formations of
the solar system. Usually consist
of the nucleus of dust and ice
with a tail.
Kuiper Belt
-Kuiper Belt: A region of
space outside the orbit of
Neptune that contains dwarf
planets and other small
objects. This region extends
from around 40 AU to 80 AU
and is shaped in orbit around
the sun as a donut ring. The
sun’s outmost reach is said to
be within the Kuiper Belt,
from where the solar system
ends and begins interstellar
space, known as the
heliopause.
•What sort of objects are
contained in the Kuiper Belt?
Oort Cloud
-The Oort Cloud: A huge spherical region of
small, deep frozen objects that form the nuclei
of comets. This region begins at about a half
a light year radius from earth to 1.5 light years
(or 50,000 AUs). It was proposed by Dutch
Astronomer Jan Oort when studying comets.
Noticing that they all had their aphelia, or
farthest distance from the sun, in this region,
possibly indicating that this is where comets
are coming from and returning to. The Oort
Cloud is estimated to contain a trillion
dormant comets.
•What sort of objects originate in the Oort
Cloud?
•What is the radius of the Oort Cloud from the
sun?
Star Formation
-Star Formation: Stars form from dense regions
of great gas and dust clouds within a galaxy,
usually nebulas. By gaining enough mass and
gravity, the star begins to emit radiation and
ultimately create enough heat within the core to
cause nuclear fusion. Finally when the star gets
hot enough, the true hydrogen fusion within the
star begins, giving birth to a very hot star
emitting a lot of energy from the hydrogen
fusion throughout the core.
•What type of fusion must occur for a star to
form?
Stars
Globular Clusters: A distinct, densely packed ball
of stars that can approach a population density one
thousand times greater than our stellar
neighborhood.
•What type of object is displayed in the image?
1987A Supernova: After and Before
Type 1a Supernova: The collapse of a existing
white dwarf usually in a binary star system that
gains mass from its companion and results in too
much fusion of carbon and oxygen.
•Type 1a Supernova consists of what type of star?
Type II Supernova: An explosion that marks the
demise of a star of very high solar masses or more.
Either a neutron star or a black hole is left over.
•What type of object is left over from a Type II
Supernova?
Stars
Eclipsing Binaries: Two gravitationally
bound stars that orbit around each other
causing their orbits to bring one star in
front of the other, giving eclipses of each
other.
•What type of object emits the given
light intensity?
X-ray Binaries: Binary Star system in
which illuminate with x-rays. The x ray
emissions are caused from matter being
transferred from one star to the other
releasing gravitational potential energy.
These two stars usually consist of a normal
star with a smaller white dwarf, neutron
star or black hole.
•Identify the object.
Stars
Epsilon Aurigae: A eclipsing binary
star system in the constellation
Auriga. It has a period of 27.1 years
and the eclipse lasts around 640-730
days. The secondary star is believed
to be a semitransparent star, which is
a type of transparent shell star.
•What type of object is Epsilon
Aurigae?
Galaxies
-Galactic Structure: Formed after the events of the Big Bang due to
formations of dark matter and fluctuations from the aftermath of the Big
Bang.
5 Types of Galaxies:
•Spiral
•Barred spiral
•Elliptical
•Irregular
•Ring
•Interacting
Types of Galaxies
Spiral
Barred Spiral
Elliptical
Irregular
Ring
Interacting
Galaxies
-Active Galactic Nucleus (AGN): The center
of a galaxy that emits a much higher
luminosity over the electromagnetic spectrum
than most galaxies. Any galaxy containing an
AGN is considered to be an Active Galaxy.
This emission of energy is the result of the
build up of mass at the galaxy’s massive
black hole at its center.
•
•
What galaxy is pictured?
A: NGC 2623
Two spiral galaxies merging into one and forming a single unified center
or a active galactic nucleus (AGN).
Galaxies
-Galaxy Cluster: A collection of
dozens to thousands of galaxies that
are bound together by gravity.
These are the largest objects in the
universe as they span across
hundreds of millions of light years
across space.
Fornax Cluster
Local Group
Groups of Galaxies: Dozens of galaxies that are grouped together
within a few megaparsecs of each other. Our own galaxy is within the
Local Group of galaxies that consist of around 40 galaxies.
• Which Group of Galaxies is the Milky Way part of?
Andromeda
Galaxy
Cosmos Objects
-Quasars: A very bright, distant core of
an extremely powerful active galaxy.
These objects are the brightest objects
in the cosmos and are identified
through radio emissions and visible
light. At the center is a very powerful
black hole that emits a lot of energy,
equivalent to a trillion times that of the
sun.
Black Holes
Black holes: A concentration of mass with a gravitation field so
strong that within a certain radius, nothing can escape it, not even
light. These are usually the result of massive stars collapsing in on
themselves under their own weight.
Supermassive Black Holes: The result of collapsing gas clouds or
merging black holes that are usually found at the center of a galaxy.
•What is the difference between a black hole and a supermassive
black hole?
Pulsating Variables
-Cepheid: Type F to K supergiant stars
that pulsate with a period of 1 to 70
days. They are brighter than RR Lyrae
Stars
Two Types:
Population 1: Young Massive Stars
Population 2: Old Fainter Stars on an
average of 1.5 in magnitude
-RR Lyrae Variables: Type A stars that
do not vary greatly in magnitude (1 or 2
degrees of magnitude) that have a period
of an hour to a day.
•Identify the graphs for each type of
Pulsating Variable.
Deep Sky Objects
MACSJ0717.5+3745: A
collision of 4 separate galaxy
clusters, one of the first to be
discovered.
SN 2006gy: One of the brightest stellar
supernovas, it was a high energy supernova
from a very large star in a distant galaxy. It is a
pair-instability supernova, meaning a massive
explosion from the star that does not leave a
black hole.
Deep Sky Objects
SN 1996cr
A very close supernova located near
the Circinus Galaxy. It is one of the
brightest supernovas discovered using
radio and X-ray technology.
NGC 4603
NGC4603: A Spiral Galaxy located about 108
million light years away and is located in the
constellation Centaurus.
JKCS041: A Galaxy cluster that
was discovered to be one of the
farthest objects at around 10
billion light years away.
Distance Modulus Formula
d = 10(m-M+5)/5
D = Distance to Star
m = Apparent Magnitude
M = Absolute Magnitude
Hubble’s Law
-Recessional Velocity =
(Hubble’s Constant) * (Distance)
Or
V=H*D
V = Observed Velocity of the Galaxy (km/sec)
H = Hubble’s Constant ~ 77 km/sec/Mpc
(Confirmed by NASA’s Chandra X-Ray
Observatory)
D = Distance of Galaxy (Mpc)
Kepler’s Laws
• What are Kepler’s Laws? Three laws
determined by Johannes Kepler, that describe
the elliptical motions of planets in their orbits.
What are Newton’s 3 Laws?
• 1st – Force causes motion.
• 2nd – Net Force = (constantmass)(acceleration)
• 3rd – If object A exerts a force on object B,
then object B exerts an oppositely directed
force of equal magnitude on A.
Units of F =
kg(m/s^2)
Magic letter g =
9.8 m/s^2
Gravitational Attraction
• What is the gravitational constant of universal
gravitation? 6.67x10^-11 Nm^2/kg^2, where
m1 and m2 equal the masses, and r equals the
distance between the particles.
F=-Gm1m2/r^2
Spectra

Measured by spectrograph

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Prism or diffraction-grating based
Magnitude vs. wavelength

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
Continuum (thermal blackbody)
Emission lines (chemical)
Absorption lines (chemical)
Spectra Applications

Measuring movement (redshift)

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Galactic expansion
Galaxy spin-rates
Exoplanet transit identification
Identifying chemical compositions

Gaseous nebula and star-forming regions
Stellar Magnitudes

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
Logarithmic brightness scale centered at Vega
(magnitude 0 star of the constellation Lyra)
Brighter things have smaller magnitude
numbers, while dimmer things have large
magnitudes
Absolute vs. apparent (integrated)
magnitudes


Absolute requires knowledge of object size and
distance
Apparent is simply how bright something “looks”
to us
Stellar Classifications

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O B A F G K M - “Oh be a fine girl, kiss me”
O is hottest (blue), M is coolest (red)
B: Bright and blue [e.g. Pleiades]
A: White or bluish-white [e.g. Sirius]
G: Yellowish [e.g. Sun]
K: Giants/supergiants, reddish [e.g. Arcturus]
M: Most common, very red [e.g. Betelgeuse]
Hertzsprung-Russel Diagram



Shows intensity vs spectral type
Intensity measured in two photometric bands,
B and V (B ~ Blue, V ~ Green)
Shows the aging of stars (stellar evolution)

Main sequence
Light Curves

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A plot of magnitude vs time
Common applications
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Binary/Variable star observation
Planetary transit searches
Asteroid modeling